Air pollution is a substantial problem for many developing countries. One type of air pollution is caused by particulate matter that contains microscopic solids or liquid droplets, which can be inhaled and cause serious health problems.
Particulate matter (PM) may also be called particle pollution, which is a mixture of solid particles and liquid droplets found in the air. Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. Others are so small they can only be detected using an electron microscope or other instruments. Currently, to measure the level of particulate matter (such as PM2.5, PM10, and other fine particles) in the air, a variety of particulate matter measuring instruments have been introduced, for example, portable haze detectors. However, particulate matter measurement values obtained by these particulate matter measuring instruments may generally be affected by the temperature and the humidity. Thus, the particulate matter measurement value may not be accurate. There is a need for better measurement methods and devices to obtain more accurate PM measurement values.